Impact of nitrogen reduction and controlled-release fertilizers on maize yields and soil inorganic nitrogen in the Yellow River irrigation area of Ningxia
We sought to investigate the impact of different nitrogen application modes on spring maize yields and soil inorganic nitrogen dynamics in the Yellow River irrigation area of Ningxia.Employing a complete randomized design,maize was selected as the research subject and five treatments were established:no nitrogen fertilizer application(CK),conventional urea application by farmers(CF,N 450 kg·hm-2),equimolar controlled-release fertilizer substitution(T1,N 450 kg·hm-2),conventional nitrogen reduction(T2,N 315 kg·hm-2),and nitrogen reduction combined with controlled-release fertilization(T3,N 315 kg·hm-2).The study aimed to analyze the effects of nitrogen reduction and controlled-release fertilizer treatments on maize yields and soil inorganic nitrogen status.The results indicated that over two consecutive years(2021 and 2022),T3 treatment exhibited the most significant annual yield increase,with notable improvements in yield components,specifically a substantial increase of 11.83%and 28.94%in average hundred-grain weight and ear grain weight,respectively,accompanied by a significant reduction(67.87%)in average ear tip length.Different nitrogen reduction and controlled-release fertilizer treatments revealed no significant impact on NH+4-N content in the 0-120 cm soil layer over two years but exhibited significant effects on soil NO-3-N and total inorganic nitrogen levels.During the harvest period,the T3 treatment demonstrated the lowest average accumulation of NO-3-N and inorganic nitrogen,reaching 210.01 kg·hm-2 and 298.40 kg·hm-2,respectively.The results of two consecutive years of nitrogen reduction and controlled-release fertilization revealed that the T3 treatment significantly enhanced nitrogen use efficiency,nitrogen agronomic efficiency,and nitrogen partial factor productivity by 21.93%,10.42 kg·kg-1,and 21.89 kg·kg-1,respectively,compared to the CF treatment.In summary,the application mode of combined nitrogen reduction and controlled-release fertilization with a total nitrogen application of 315 kg·hm-2(T3)emerged as the optimal fertilization strategy for spring maize in the Yellow River irrigation area of Ningxia,thereby balancing ecological and economic benefits.
spring maizecontrolled-releasenitrogen reductionyieldinorganic nitrogen
万方数据
维普
